The bq25120 is a highly integrated battery charge management IC that integrates the most common functions for wearable devices: Linear charger,regulated output, load switch, manual reset with timer, and battery voltage monitor. The integrated buck converter is a high efficiency, low IQ switcher using DCS control that extends light load efficiency down to 10-μA load currents.The low quiescent current during operation and shutdown enables maximum battery life. The device supports charge currents from 5 mA to 300 mA. The input current limit, charge current, buck converter output voltage,LDO output voltage, and other parameters are programmable through the I2C interface.